Ken Livingstone today launched a second blistering attack on the Daily Mail group, saying it would have been "at the front of the queue of collaborators" had the Nazis won the war and branding its papers among "the most reprehensibly edited" organs in the world.

Defiantly refusing to apologise for likening a reporter on the Daily Mail's sister paper, the Evening Standard, to a "concentration camp guard", the London Mayor said it would be easy to buy his way out of the current storm but it would be insincere.

"It would be very easy for me to buy off media pressure by lying but I am not going to do it."

At a routine press conference this morning, Mr Livingstone insisted his remarks were justified, reiterating his claims at the London Assembly yesterday that he had suffered a 24-year hate campaign by newspapers, particularly those within the Daily Mail group.

"Although we uniquely have some brilliant newspapers and first-rate journalists, their standing is dragged down by what must be some of the most reprehensibly managed, edited and owned newspapers in the world.

"They have a disgraceful record, none more so than the Daily Mail," he said.

"When it was first set up [in 1896] its first campaign was against Jewish refugees coming to London from the pogroms. It continued its anti-Semitism in the 1930s, fighting any proposals that Jewish refugees fleeing Hitler should be admitted to this country."

He said the Mail had run stories supporting fascism and that its owner, the 1st Viscount Rothermere, the great-grandfather of the present proprietor, had welcomed Hitler's rise.

"Had Britain lost the war and had the Nazis controlled Britain, Lord Rothermere and his cohorts would have been at the front of the queue of collaborators."

He said the Mail had continued to discriminate against minorities since the war, demonising first Irish immigrants and now asylum seekers.

'Dacre wanted an editor he could control'

"I deplore them [the Associated papers] and regret they ever existed," he said.

He said he recognised that the Evening Standard in the 1930s was owned not by Associated but by Lord Beaverbrook, that it opposed appeasement and that it was edited at one stage by the future Labour leader, Michael Foot.

"While Max Hastings was editor, I had no qualms. Once Veronica Wadley took over it turned into a clone, it was effectively the Evening Mail. Not exactly the same - that level of racism and xenophobia would not play well in London.

"It's a quite different paper - I think that's what Paul Dacre wanted. He wanted an editor he could control and bring it into line to reflect the general views of the Mail group."

Mr Livingstone dismissed the idea that because the Standard had endorsed his re-election as mayor last year it was therefore not true that the paper had victimised him.

"Veronica Wadley says they supported me - but it was only because they hated Steven Norris more than they hated me... Norris was a Tory candidate who referred to Paul Dacre in language I could not use before the 9 o'clock watershed."

He said the Standard had wanted to support Liberal Democrat Simon Hughes but had given up on him when he seemed unlikely to win.

Mr Livingstone said the vast majority of voters "would see through" the current row and understand that he was justified in attacking the Evening Standard reporter.

'Offensive yes, racist no'

"You can make a case that my remarks were offensive, but you can't make a case that my remarks were racist."

The row first erupted when MediaGuardian.co.uk revealed the exchange between Mr Livingstone and a Standard reporter, Oliver Finegold, after a party held to celebrate the 20th anniversary since Chris Smith came out as a homosexual.

A leaked transcript of the exchange was handed to MediaGuardian.co.uk and the following day the Standard revealed it had a tape recording of the exchange, making the story headline news on both the BBC and ITV.

Jewish community leaders and Holocaust survivors have demanded an apology from the Labour Mayor but Mr Livingstone has consistently refused to apologise either to the reporter or the Jewish community.

Auschwitz surviver Gina Turgel told MediaGuardian.co.uk that she was appalled that Mr Livingstone was making light of the experience of Holocaust victims and survivors and yesterday she attended the London Assembly to hear Mr Livingstone address the protests of the Jewish community.

"How can he bring in the suffering of his family for 24 years? There is no comparison with what we went through. I would have gladly exchanged my suffering with his," she said.

Labour colleagues on the London Assembly yesterday backed a motion, passed unanimously, calling for him to withdraw his remarks.

An official complaint has been made to local government watchdogs by the Board of Deputies of British Jews, demanding an investigation by the Standards Board of England.

Mr Livingstone said he was prepared to ride this storm out and would not change his views just because criticism was being heaped upon him.

"I have been through several media firestorms and I have always taken the view that if I have made a mistake I will apologise.

"There must have been 20 instances like this over the last 24 years.

"I have never, in response to any of that, modified a policy I believed to be right or modified a position I believed to be right and I don't intend to now.

"Because if I do that, effectively you hand power over your policies and position to the editors of papers."

He said he did recognise, however, that the Standard was different under its former editor, Sir Max Hastings, and he would be delighted if he came back.

And he said he had "no problem" squaring his attacks on the Standard with the fact that he worked as a restaurant critic for ES magazine between 1996 and 2000.

"Whilst Max Hastings was the editor of the Evening Standard it went through a period when it was absolutely excellent. It was a serious journal central to political debate in London and set much of the agenda that led to the creation of the mayoral system.

"His five years stand out as a high point in the history of the Evening Standard. I have no complaint about the conduct of his newspaper. Subsequently I have had disagreements.

"You couldn't say, 'I'm not going to work for a paper run by Max Hastings because of what his predecessors did'... If Max Hastings were to come back I would be delighted and would work for him again."

The Standard had dubious motives for covering Smith party

Mr Livingstone conceded that the Standard had a right to report on the party last Tuesday night but said the paper had "dubious motives" for sending a reporter and photographer to a gay and lesbian event.

"You have to ask, out of all the receptions put on here, why uniquely was this the only one where the Evening Standard photographed everybody leaving, which some people might find intrusive.... Once I had indicated I did not want to get into a debate, it was inappropriate for a reporter to pursue me along the public pathway barking the same question.

"It's inappropriate that out of all these receptions they chose the lesbian and gay one. Why are they photographing everyone? What possible reason has the Evening Standard for taking photographs? I think there are dubious motives there, frankly.

"I may very well be offensive, these are matters of personal judgment. What I was not, was racist."

Asked if he was aware of the offence taken by people who might not share his personal animus against the Standard, he said he "shared their pain".

"I share the pain they feel the way this story has been whipped up and given legs. It has been orchestrated by the Evening Standard, they did not run with the story but they put in a lot of work going mad, splashing the story across the front page and linking it with the Arab-Israeli conflict."